157 Tamil asylum seekers sent from Curtin detention centre to Nauru

The 157 asylum seekers at the centre of a High Court battle have been sent to Nauru after they declined to return to India.

The Sri Lankan Tamils set sail from the Indian state of Pondicherry in mid June in a bid to seek Australia's protection.

The group, which includes families and children, were intercepted by Customs officials and held at sea for nearly a month.

Refugee advocates launched a High Court challenge before they were eventually taken to the Curtin Immigration Detention Centre in remote Western Australia.

Immigration Minister Scott Morrison had planned to have Indian officials assess them in the hope they would choose to return to live in India.

But all have refused to meet Indian officials and they have now been taken to Nauru to have their claims for asylum processed.

Mr Morrison says they could have avoided being sent to Nauru if they had been willing to return to talk to Indian officials.

"There are 50 children now who have been transferred to Nauru who might otherwise have been going back to India, where they would've had families and friends and where they were going to school," he said.

"I'm very disappointed that hasn't been taken up."

Opposition immigration spokesman Richard Marles says the group should have been taken straight to Christmas Island for processing, rather than moving them around for weeks.

"The only reason they have been put through this wretched roller coaster has been to protect Scott Morrison's personal political scoreboard, which, for what it's worth, today is in tatters," he said.

Under the Government's policy, the asylum seekers will not be re-settled in Australia.

Greens immigration spokeswoman Sarah Hanson-Young says the Government has mismanaged the case from the start.

"First they pretended they didn't even exist. Then they refused to be upfront with the Australian people with what was going on," she said.

"Now they've secretly smuggled them out to Nauru to keep them away from lawyers and advocates and this Government is making policy up on the run."

Lawyer accuses Government of 'trafficking'

Lawyer George Newhouse challenged the group's detainment at sea in the High Court and the group was eventually brought to the mainland.

Mr Newhouse says the asylum seekers were not given the chance to talk to their lawyers about their options before they were moved to Nauru.

"We have not had opportunity to inform our clients of their rights and options," he said.

"It may be that we might encourage them to take up such an opportunity but we haven't even had the opportunity to talk to them.

"These people were trafficked under the cover of darkness. This is the second time they've been disappeared.

"They've been taken on the high seas, held prisoner for a month then shipped around to Cocos Islands, then the Curtin detention centre, and now in the middle of the night taken to another place."

Mr Morrison said the group had access to their lawyers prior to declining a meeting with Indian officials.

"They had access to their lawyers and subsequent to that access 157 people coincidentally decided that they were not going to take up the offer of consular assistance," Mr Morrison said.

"Only those who were in that room will know what was done ... it would seem if they wanted them to talk to India and consular officials they weren't terribly persuasive about that. And that's unfortunate."

Mr Newhouse has provided the ABC an extract of a letter from Shine Lawyers to the Indian High Commission on July 27.

He says it shows the lawyers were taking a cooperative approach to the interviews.

"Due to the complexity of the legal issues currently arising and the significance of the solicitor-client relationship that exists in this matter we request that the Indian government instruct lawyers who may be able to act in this matter so that we can seek to engage in a cooperative approach with those lawyers acting on the Indian government's behalf," the extract reads.